It began as a physics archive, called the LANL preprint archive, but soon expanded to include astronomy, mathematics, computer science, nonlinear science, quantitative biology and, most recently, statistics. Its original domain name was xxx.lanl.gov. Due to LANL's lack of interest in the rapidly expanding technology, in 1999 Ginsparg changed institutions to Cornell University and changed the name of the repository to arXiv.org.[9] It is now hosted principally by Cornell, with 8 mirrors around the world.[10]

The annual budget for arXiv is approximately $826,000 for 2013–17, funded jointly by Cornell University Library, the Simons Foundation (in both gift and challenge grant forms) and annual fee income from member institutions.[12] This model arose in 2010, when Cornell sought to broaden the financial funding of the project by asking institutions to make annual voluntary contributions based on the amount of download usage by each institution. Annual donations were envisaged to vary in size between $2,300 to $4,000, based on each institution’s usage. As of 14 January 2014[update], 174 institutions have pledged support for the period 2013-17 on this basis, with a projected revenue from this source of approximately $340,000.[13]

Although the arXiv is not peer reviewed, a collection of moderators for each area review the submissions; they may recategorize any that are deemed off-topic,[15] or reject submissions that are not scientific papers. The lists of moderators for many sections of the arXiv are publicly available,[16] but moderators for most of the physics sections remain unlisted.

Additionally, an "endorsement" system was introduced in 2004 as part of an effort to ensure content that is relevant and of interest to current research in the specified disciplines.[17] Under the system, for categories that use it, an author must be endorsed by an established arXiv author before being allowed to submit papers to those categories. Endorsers are not asked to review the paper for errors, but to check whether the paper is appropriate for the intended subject area.[15] New authors from recognized academic institutions generally receive automatic endorsement, which in practice means that they do not need to deal with the endorsement system at all. However, the endorsement system has attracted criticism for allegedly restricting scientific inquiry.[18]

A majority of the e-prints are also submitted to journals for publication, but some work, including some very influential papers, remain purely as e-prints and are never published in a peer-reviewed journal. A well-known example of the latter is an outline of a proof of Thurston's geometrization conjecture, including the Poincaré conjecture as a particular case, uploaded by Grigori Perelman in November 2002. Perelman appears content to forgo the traditional peer-reviewed journal process, stating: "If anybody is interested in my way of solving the problem, it's all there [on the arXiv] – let them go and read about it."[19] Despite this non-traditional method of publication, other mathematicians recognized this work by offering the Fields Medal and Clay Mathematics Millenium Prizes to Perelman, both of which he refused.[20]

While the arXiv does contain some dubious e-prints, such as those claiming to refute famous theorems or proving famous conjectures such as Fermat's last theorem using only high-school mathematics, they are "surprisingly rare".[21] The arXiv generally re-classifies these works, e.g. in "General mathematics", rather than deleting them.[22]

Papers can be submitted in any of several formats, including LaTeX, and PDF printed from a word processor other than TeX or LaTeX. The submission is rejected by the arXiv software if generating the final PDF file fails, if any image file is too large, or if the total size of the submission is too large. arXiv now allows one to store and modify an incomplete submission, and only finalize the submission when ready. The time stamp on the article is set when the submission is finalized.

The standard access route is through the arXiv.org website or one of several mirrors. Several other interfaces and access routes have also been created by other un-associated organisations. These include the University of California, Davis's front, a web portal that offers additional search functions and a more self-explanatory interface for arXiv.org, and is referred to by some mathematicians as (the) Front.[23] A similar function used to be offered by eprintweb.org, launched in September 2006 by the Institute of Physics, and was switched off on 30 June 2014. Google Scholar and Windows Live Academic can also be used to search for items in arXiv.[24] Finally, researchers can select sub-fields and receive daily e-mailings or RSS feeds of all submissions in them.